Finger inserts are widely known and used to provide better control of a bowling ball. Such inserts typically have a body which is generally cylindrical in exterior shape to fit a hole formed in the ball. The interior cavity of the insert is configured to provide a particular advantage.
One example of such an insert is shown in Martin U.S. Pat. No. 4,585,230 (issued Apr. 29, 1986). The Martin insert has a cavity which is generally cylindrical in shape and includes a pair of adjoining planar surface portions arranged in edgewise angular relationship to one another. This V-shaped portion, contacted by the underside of a bowler's finger, is said to permit better control of the bowling ball by increasing the frictional engagement between the finger and the ball.
Another example of a finger insert is shown in Todd et al. U.S. Pat. No. 4,773,645 (issued Sept. 27, 1988). The Todd et al. insert likewise has a generally cylindrical interior cavity with a plurality of chord-like, sharp-edged ribs along one side thereof. The ribs are said to provide good frictional engagement between the finger and the insert.
Yet other examples of finger inserts are shown in Bach U.S. Pat. No. 3,784,198 (issued Jan. 8, 1974); Heimbigner U.S. Pat. No. 4,289,312 (issued Sept. 15, 1981) and Heimbigner U.S. Pat. No. 4,416,452 (issued Nov. 22, 1983). Still other known types of finger inserts are shown in the drawing and briefly described in the initial portion of the specification set out below.
While known inserts of the type described herein have been generally satisfactory, they tend to share certain disadvantages. In particular, they fail to appreciate the manner in which a finger insert may be constructed to provide a tactile indication of correct finger positioning within the insert. Another disadvantage is that such known inserts are devoid of any provision for using bowler's tape to adjust, within a range, the size of the cavity to fit fingers of different sizes. An improved finger insert which includes such features would be an important advance in the art.